If there is a genuine reason to rehome the animal then so be it.
But far far too many people few pets as disposable instead of members of the family.
So many times you see 'moving, dog needs home/cat needs home', 'have a baby and don't want to worry about the cat with it, cat must go' etc etc.
I guess I'm strange that way. I view my animals as part of the family. The only reason my dog did not come out here with me was because of being in town. My parents are keeping my dog for me as she is very much a country dog and needs hours of walkies a day (plus it gives dad a reason to get out of the house so as not to drive my mother completely insane).